The present invention relates generally to electrical device testing, and more particularly to a multiple two-axis floating split probe block assembly for testing an electrical device.
Electrical testing of electrical devices often involves insertion probing of a receptacle of the device. For example, a cellular phone often includes a receptacle configured as an array of signal points on the device under test (hereinafter referred to as the “system connector”). The device, in this example a cellular phone, may also include additional receptacles such as an audio receptacle into which a headset audio plug is inserted or a charger receptacle into which an A/C charger plug is inserted to charge up the device.
During or after manufacturing, various tests are performed on the device (hereinafter referred to as “device under test” or “DUT”). Typically at least one or more tests require insertion probing of two or more of the DUT receptacles. Insertion probing involves the insertion of a probe into the mating DUT receptacles such that the probes and DUT receptacles make electrical contact. The electrical contact is the means through which the probe stimulates and/or receives measurement signals from the DUT. Although insertion probing is itself a conceptually straightforward idea, the design of the probe that is used for this purpose does require several important considerations. First, due to manufacturing limitations, at least some error relative to specification typically exists in the precision of the location of the electrical pads of the device which the probe must electrically contact. Thus, over hundreds and thousands of a given device to be tested, the probe must be designed to take into account the pad location tolerances such that it can reliably make electrical contact with each DUT to be probed.
In order to account for the pad location tolerances of a given DUT design, a “floating” probe block is sometimes used. In a floating probe block, the probe is attached to a block which is encased in a substantially conforming frame that holds the block in place while allowing the block a small amount of “wiggle room” within the frame. This solution allows the receptacle to assist in aligning the probe within the receptacle. However, the use of a single floating probe block is problematic when probing two or more receptacles on the DUT (e.g., charger plugs and audio plugs).
Due to manufacturing limitations, at least some error relative to specification typically exists in the precision of the location of the DUT receptacles relative to the DUT case and also relative to the other DUT receptacles on the DUT. Thus, over hundreds and thousands of a give DUT to be tested, the probe block must be designed to take into account the receptacle location tolerances such that the probes of the probe block can reliably make electrical contact with each DUT receptacle to be probed.
A single probe block cannot account for these differences. The single probe block aligns to one of the receptacle features on the DUT, while forcing the other probes into their respective receptacles. This force is a major source of wear on both the DUT being probed and the probe block, and also can cause connector failure on the DUT.